Piston for internal-combustion engines



April 6, 1946. c. v. BRATZEL 2,398,577 I PISTON FOR INTERNALCOMBUSTION ENGINES Filed June 1., 1944 v 2 Sheets-Sheet 1 l2? @W W "WEED-mil Inventor GEO/=20: If 51897251.,

y @mw April 16, 1946. G. v. BRATZEL PISTON FOR INTERNAL-COMBUSTION ENGINES Filed June 1, 1944 2 Sheets-Sheet 2 Inventor 9 Geo/e05 VBBTzEL,

Patented Apr. 16, 1946 g PISTON FOR INTERNAL-COMBUSTION ENGINES George V. Bratzel, Menlo Park, Calif.

Application June 1, 1944, Serial No. 538,254

2 Claims.

the old piston rings can be taken off and the piston cleaned and new rings put on. The piston is now ready' for re-instalment.

The main object of the present invention is now to avoid all this labor, waste of time and consequent expense by providing a piston that can be repacked in place, that is, the old packing rings taken ofi and replaced by new ones without removing the entire piston, but only by taking ofl the engine head, no radical changes in the construction of the engine being needed.

This invention is illustrated in the accompanying drawings in which: 7

Figure I 1 is a vertical, fragmentary section showing the bore of the combustion chamber with piston and packing rings in position.

Figure 2 is a. verticalsection of a piston body with removable head or cap assembled.

Figure 3 is an elevation of the piston body in Figure 2 with the head or cap lifted ofi and shown in section. t

Figure 4 is a top plan View of the piston body in Figure 3 without the head or cap.

Figure 5 is a section along the line 5-5 of Figure 3.

Figure 6 is a view similar to Figure 2 of a modified form Of piston consisting of a core por tion and a ring shell portion.

Figure 7 is a. vertical section of construction similar to Figure 2, but with the cap threaded on the spider and two cap screws for securing the cap or head from the spider.

Figure 8 is a view similar to Figure 3 of the modification in Figure '7 showing the position of two cap screws for securing the removable head on the body.

Figure 9 is a top plan view of the piston body in Figure 8,

Figure 10 is a cross section along the line I0I II of Figure 8, and

Figure 11 is a top plan view of the cap in Figure 8.

In the accompanying drawings the same numerals refer to the same details.

Referring first to Figures 1- to 5, the piston, which is of standard type, is here made in two main partsnamely, the cap I2 and the body I3 two upper packing rings I5, while spacefor a third ring I5a is furnished just below the bottom surface It of the cap I 2 around a shoulder Ila having oil vents I3b. This permits the removal of the third packing ring as soon as the cap I2 has been detached, while the two first rings I5 remain on the cap to be taken away with the head, the piston body stays in place in the engine cylinder I1. I

The upper end of the piston body I3 is formed as a spider or neck I30 of smaller diameter than the body I 3 and fits snugly in a recess orchamber I9 in the 'cap- I2, when the cap is secured in position on the piston body by a capscrew I8, threaded in the spider I30. H I

After replacing the two upper packing rings I5 on the cap I2, and inserting a third ring around the shoulder I3b of the spider, the cap or head I2 is then ready to be pushed down over the spider I30 until its shoulder I6 meets with,

the installed third ring I511.

The roof portion of the head I2 has a serrated neck on its underside at I2b, see Figure 3, around the hole Ila which runs right through the roof for cap screw I8, to coincide and interlock with serration lite on top of spider or neck I3c around the threaded hole for the cap screw I8. When the two rings I5 have been replaced by new ones, the head I2 is ready to be pushed down over neck or spider I30, Figures 2 and 3, and. this will cause the serrations IZb to interlock with I 3e so that head I2 will not turn and become loose. A metal packing washer is preferably placed in the recess I2d of the screw hole in the center of the head I2 and thecap screw I8 screwed down into place as shown in Figure 2. When the cap screw I8 is drawn tight, a tiny hole I2g is drilled at each end of the slot in the cap screw and into the wall at the recess 2d of head or cap I2. These holes are drilled in inclined direction slightly downward and about an eighth of an inch deep, see Figure 3, providing a hole for a wire pin I2), which is out about a quarter of an inch longer than the y then flattened down into the groove I2h of the recess or chamber I 9 on the underside of the head with two grooves I4 in the cap or head I2- for the I2 and run down through flutes 20a provided in oer-ice without spider.

the side walls of neck or spider l8c, out through holes 20b and thence into the crankcase. The holes 20b are drilled radially into the side wall of the spider [30 above the shoulder I81: and the oil vents l3b as here shown but the flutes may continue straight down for the convenience of casting. The crank pin bearing is indicated at 28 in Figures 1 and 2.

In Figure 6 is shown a modification in which this piston has a nearly full length core 25 with a neck 25a of smaller diameter than its body and a ring shell 26 surrounding the core and having the full length of the piston. The shell preferably has a cap 26a and a skirt 28b separable along the surface It. The cap 28a has packing grooves 28d on the outside and a recess or chamber 28c. inside closely fitting the neck 25a of the core 25. This is the piston construction suitable for all new cars, while the construction in Figure 2 is intended for use on old cars in order to make exchange of packing rings l5, l5a possible without dismounting the crankcase. v

The crank pin bearing 21 in Figure 6 extends only through the walls of the core 25, and all in Figures 2, 3 and 4. Instead of making the cap proper 28a and the skirt 26b as a'unit, they may be separated along line It flush with the topsurface of the third packing ring use. This will make the three p cies alike as regards diameter and depth of cap. q

Should it be impracticable on some motors to use a center cap screw then two or more threaded holes 28 are provided in top of core 25, see modification in Figure 7, and two or more small" cap screws, andthe head of the shell reinforced accordingly, see Figures .7 to 11. 7

Figures 7 and 8 show that the head or cap 28 instead of being smooth faced as in Figures 1 to 5, is made to screw on like a jar cover and is locked with two cap screws 38 engaging in theneck 3la of threaded sockets 29 in the piston body 8|. To remove head or can 28 the usual spanner holes I orfiats provide hold for a face spanner wrench.

The threaded type, Figures 7 and 8, can be made The center of the core is, howe er, reinforced around the threaded holes 28 for the cap screws 30. If oil is to circulate then the radial holes 28b-the flutes 20a have to be provided, and the latter should be cut straight up v and down not quite as deep as the threadaso as to be open when the head 28 is screwed home on' the body 3|. The flutes can be made'todrain straight down or through the radial holes-28b.

radial oil vents connecting said flutes with In Figure 6, the piston core 25 is made with a shell 28. The shell is pushed over the core and held in place with a cap screw l8 and locked with wire pin, as described in connection with Figures 1 to 5. In case the shell is made in two pieces, only the cap proper 26a need be remoyed and the skirt 26b left on the core to exchange the packing rings [5, lid.

The construction witl r; core and shell and with two cap screws instead of one, are self-explanatory and should easily be understood from the foregoing description. It will, therefore, be clearly seen how this improvement can be applied both on old and new motors and make considerable saving in repairs.

It is to be understood that the invention as here disclosed is not limited to the details here described and shown but that the same may be varied widely without departing from the spirit of the invention as defined by the subjoined claims.

Having described the invention, what is claimed as new is:

1. In a motor with expansible-type chamber, a divisible piston adapted for repacking in position; comprising a cap or upper portion and a skirt or lower position and means for firmly assembling and quickly disassembling said portions; said skirt provided with bearings for a crank pin, and a neck fitting snugly in the cap and being provided with an abutment for said cap and providing a seat for receiving a lowermost metal packing ring; said cap having grooves for other metal packing rings, and being adapted to abut with its bottom surface against the said lowermost packing ring, interlocking serrations provided between adjacent surfaces of the cap and the neck of the skirt to prevent relative turning; said neck of the skirt being externally fluted and provided with radial oil vents connecting said flutes with its hollow interior.

2. In a motor with expansible-type chamber, a

divisible piston adapted for repacking in position;

pin and a neck fitting snugly in said cap; said outer sleeve having an abutment for said cap providing a seat for said lowermost metal packing ring; interlocking serrations provided between adjacent surfaces of the cap and the neck of the skirt to prevent relative turning; said neck of the skirt being externally fluted and provided with its hollow interior.

GEORGE V. BRATZEL. 

